Cause

The arrow heads of two cross-referencing interruption points are pointing to one another.

Solution

Rotate one of the cross-referencing interruption points so that the arrow head of one points to the bottom of the other interruptions points' arrow head. To do this, double-click on the interruption point you want to rotate. In the Properties <...> dialog, bring the Symbol / function data tab to the front. Rotate the interruption point by 180° with the help of the drop-down list Variant.

Refresh the connections and then start a new check run.